I need to perform multithreading on postfix mail server.
I read about POSIX multithreading but could it be linked to postfix smtp server and if yes then how?
System Specification: ubuntu 14.04 LTS and ...

The reference about poll() just says “The specified fd value is invalid. This flag is only valid in the revents member; it shall ignored in the events member.”.
That's not clear (at least to me): if ...

I just became really confused by the implementation of bash's cp -R command compared to how POSIX words what should happen
Given the posix definition, I would expect cp -R srcDir existingDestDir to ...

In most POSIX compliant shell like bash. ksh, dash, mksh, pdksh, when variable assignment occur, field splitting and filename expansion (and brace expansion if the shell supports) are not performed in ...

I've written a script which runs in a strictly POSIX compliant shell without trouble on my machine but a buddy of mine couldn't execute it. It seems as if his machine has different versions of tools ...

On GNU/Linux system I seen only positive PIDs, but when kernel panic occured I seen info about process with PID=0. What's it?
On Minix 3 I seen processes with negative PIDs. Minix is POSIX-compatible ...

In this edit
Stéphane Chazelas POSIXifies (again) my sed formatting by inserting an -expression break and another -expression statement. Now, I might just ask him why in the comments, I suppose, but ...

I don't think the shell/utilities in historical Unix nor in something as "recent" as 4.4BSD supported using a double-dash(or two consecutive hyphens) as an end of options delimiter. With FreeBSD, you ...

Linux has a /proc directory and file‑system, which as far as I can tell, is not part of POSIX. In each /proc/$PID subdirectories, is a symbolic link, cwd, pointing to the actual working directory of ...

I would like to use an interactive posix bash shell but the autocompletion feature doesn't work. When i type the tab character it simply prints a tab. The tab completion only works when i'm on a non ...

I would like to use an interactive posix bash shell but the autocompletion feature doesn't work. When i type the tab character it simply prints a tab. The tab completion only works when i'm on a non ...

I would like to understand the term "system call". I am familiar that system calls are used to get kernel services from a userspace application.
The part i need clarification with is the difference ...

Can someone put these tools in order of portability? Which of these is certain to be found on even the most minimal *nix systems? Is any of them 100% sure to be present? My guess is that the order is ...

I know that set is used to manipulate environment variables, but I want to make myself sure - these alterations are not permanent, right? I mean once I close shell and reopen it, no changes will be ...

Is there a standard (POSIX) way of asking the user some data from within a shell script, with read for example, while allowing live edition of the text being typed (what readline does)?
I know bash ...

How can we obtain a temporary file name in a standard-conforming shell script (using no commands or extensions which are not described the 2013 edition of IEEE 1003.1).
There doesn't appear to be any ...

I know some uid and gids that I dont know who they belong to and they are not in /etc/passwd (could be LDAP or from another system). How do I get Id info from only uid or gid preferably without using ...

I have been adjusting to using GETOPT and GETOPTS in my shell scripts and custom functions to enable me to use the functions that I create more flexibly. After using a number of UNIX functions I have ...

If I want to add all of the members who belong to the supplemental group web_users to the apache group (as an additional supplemental group) can I just add web_users group to the apache group? Or do ...

I have seen Bash scripting guides suggesting the use of array for working with filenames containing whitespace. DashAsBinSh however suggests that arrays are not portable so I am looking for a POSIX ...